The present invention relates to a knowledge base generating system for generating a knowledge base in which different model bases have mutually retrievable data, which knowledge base is applied to knowledge based expert systems such as a fault diagnostic system or a computer-aided design support system.
In a knowledge based expert system such as a fault diagnostic system or a computer-aided design support system, it is desirable that much expert knowledge be stored in a knowledge base in a well-arranged manner. FIG.1 shows a conventional knowledge base 50 provided in a fault diagnostic system for diagnosing faults in a target machine. In this knowledge base 50, a number of different sets of knowledge N1, N2, . . . , Nn concerning causal relations between causes and effects are generated as shown in FIG. 1, and there may be many sets of knowledge having similar causal relations in the knowledge base 50. Especially when the target machine is a large-scale, computer-aided system, component parts of the same type are combined to construct the units of the system, and some faults take place in the system in a similar manner. It should be noted that a number of different sets of knowledge concerning similar causal relations exist in the knowledge base 50.
In the case of the above mentioned knowledge base 50, however, there is a problem in that the knowledge concerning similar causal relations is repeatedly input and generated. For example, when the knowledge base 50 contains one set of knowledge N1 as shown in FIG. 2A, another set of knowledge N2 is input and generated in the knowledge base 50 as shown in FIG. 2B. When it is necessary to generate a further set of knowledge N3 concerning causal relation similar to that of the knowledge N1, data is again input so that the knowledge N3 which is separate from the other sets of knowledge is generated in the knowledge base 50 as shown in FIG. 2C, although the causal relation of the knowledge N3 is similar to that of the knowledge N1. In this manner, by inputting the data for each set of the knowledge concerning similar causal relations, the knowledge base 50 containing several sets of knowledge N1 through Nn shown in FIG. 1 is built.
Therefore, in order to generate the conventional knowledge base 50, it is necessary that sets of knowledge concerning similar causal relations be generated by repeatedly inputting data for each set of knowledge. When it is necessary that many sets of knowledge concerning similar causal relations be generated in the knowledge base 50, much time and labor are required to input the data for each set of knowledge. This is inconvenient for the users. Also, it is possible that a set of necessary knowledge might be omitted from the knowledge base if an operator fails to input the set of knowledge by mistake.